More numbers spelling out Android’s pole position in the smartphone market today in the U.S. Figures from comScore (NSDQ: SCOR) say that as of the end of February, a full one-third (33 percent) of all smartphone users in the U.S. were using Android-powered smartphones, as smartphone penetration in the market is now approaching 30 percent of all mobile handsets.

At this point, it looks like Android’s gain is largely at the loss of RIM (NSDQ: RIMM), and (to a lesser extent) Microsoft (NSDQ: MSFT) and Palm: in the last three months since comScore last reported figures, the BlackBerry maker dropped 4.6 percentage points to a 28.9 percent share; while Microsoft dropped by 1.3 percent to 7.7 percent; and Palm (NYSE: HPQ) went down to 2.8 percent, a drop of 1.1 points.

Apple (NSDQ: AAPL), in third place, is at a 25.2 percent share (a rise of 0.2 percent).

In all, some 69.5 million people in the U.S. are now using smartphones, out of a total mobile user base of 234 million people aged 13 and older, says comScore in its research note. The works out to smartphone penetration of nearly 30 percent for the U.S. market.

Mobile content consumption: Given that the vast majority of feature phones are now also getting increasingly “smart”, it comes as no surprise that people are using them for a lot more than basic phone calls and texts — although text messaging, used by 68.8 percent of all U.S. mobile consumers, is still the most popular content service.

The mobile content service that saw the biggest growth over the last three months has been social networking: 26.8 percent of all users now access social networking sites on their mobile devices, a rise of 3.3 percent over three months ago.

Those who are interested in trying to figure out whether apps or web browsing is dominating in mobile content will continue to duke it out as the two remain virtually neck-and-neck as popular content formats: 38.4 percent of people have used a web browser on their devices; while 36.6 percent have downloaded apps. Both have grown just over 3 percent over three months ago.

ComScore’s breakdown of the other most-popular mobile content services:

A postscript on the growth of Android: A couple of months ago, Google (NSDQ: GOOG) put together its own video infographic demonstrating the rise. We’ve embedded it below. Worth having a look if you haven’t seen it before (of if you just want to see it again):